Based on scientific trials from around the world, experts say that COVID-19 vaccines that have reported results have shown to be close to 100 percent effective at preventing hospitalizations and deaths.
This includes vaccines with lower efficacy rates, which reflects how well the vaccine works in a controlled setting, and does not account for a vaccine’s ability to prevent serious illness.
Experts say COVID-19 vaccines are extremely effective at preventing serious illnesses, leading to lower hospitalizations and deaths.
Studies show that all approved COVID-19 vaccines are effective against the highly transmissible Delta variant.
The US Centers for Disease Control and Prevention advises the use of masks and other preventative measures even after inoculation in public indoor spaces where community transmission is high.
Efficacy reflects how well the vaccine works in a controlled setting like a clinical trial, while effectiveness is what happens in the real world. For instance, the Pfizer-BioNTech vaccine’s 95 percent efficacy means that it was 95 percent effective at preventing symptoms of covid-19 in trials, which didn’t quite reflect real-world conditions.
It is unknown how long “natural” immunity derived from a COVID-19 infection lasts, according to health experts, and public health organizations say people who have recovered from the virus should get vaccinated.